Abu al-Qasim Muhammad ibn Abbad (1023-1042), the cadi of Seville, founded the house in 1023. He functioned as the chief of an Arab family settled in the city from the first days of the conquest. The Beni-abbad had not previously played a major role in history, though the poets, whom they paid largely, made an illustrious pedigree for them after they had become powerful. The family did, however, have considerable wealth.
Al-Qasim gained the confidence of the townsmen by organizing a successful resistance to the Berber soldiers of fortune who had grasped at the fragments of the caliphate. At first he professed to rule only with the advice of a council formed of the nobles, but when his power became established he dispensed with this show of Republican government, and then gave himself the appearance of a legitimate title by protecting an impostor who professed to be the caliph Hisham II. When al-Qasim died in 1042 he had created a state which, though weak in itself, appeared strong as compared to the little powers about it. He had made his family the recognized leaders of the Muslims of Arab and native Spanish descent against the Berber element arrayed under the king of Granada.
Abbad II al-Mu'tadid (1042-1069), the son and successor of al-Qasim, became one of the most remarkable figures in Spanish Muslim history. He had a striking resemblance to the Italian princes of the later Middle Ages and the early Renaissance, of the stamp of Filippo Maria Visconti.
Abbad wrote poetry and loved literature; he also appears as a poisoner, a drinker of wine, a sceptic and treacherous to the utmost degree. Though he waged war all through his reign, he himself very rarely appeared in the field, but directed the generals, whom he never trusted, from his "lair" in the fortified palace, the Alcázar of Seville. He killed with his own hand one of his sons who had rebelled against him. On one occasion he trapped a number of his enemies, the Berber chiefs of the Ronda, into visiting him, and got rid of them by smothering them in the hot room of a bath. He habitually preserved the skulls of the enemies he had killed - those of the meaner men to use as flower-pots, while those of the princes he kept in special chests. He devoted his reign mainly to extending his power at the expense of his smaller neighbours, and in conflicts with his chief rival the king of Granada. These incessant wars weakened the Muslims, to the great advantage of the rising power of the Christian kings of León and Castile, but they gave the kingdom of Seville a certain superiority over the other little states. After 1063 Fernando El Magno of Castile and Leon assailed him, marched to the gates of Seville, and forced him to pay tribute.
The son of Abbad II, Abbad III al-Mu'tamid (1069-1091); who reigned by the title of Al-Mu'tamid - was the third and last of the Abbadids. A no less remarkable person than his father, and much more amiable, he also wrote poetry and favoured poets. Abbad III went, however, considerably further in patronage of literature than his father, for he chose as his favourite and Prime Minister the poet Ibn Ammar. In the end the vanity and feather-headedness of Ibn Ammar drove his master to kill him.
Abbad III came even more under the influence of his favourite wife, Romaica, even more than that of his Vizier. He had met her paddling in the Guadalquivir, purchased her from her master, and made her his wife. The caprices of Romaica, and the lavish extravagance of Abbad III in his efforts to please her, form the subject of many stories.
In politics Abbad III carried on the feuds of his family with the Berbers, and in his efforts to extend his dominions proved himself capable of as much faithlessness as his father. His wars and his extravagance exhausted his treasury, and he oppressed his subjects with taxes.
In 1080 Abbad III brought down upon himself the vengeance of Alfonso VI of Castile. He had endeavoured to pay part of his tribute to the Christian king with false money, but a Jew, one of the envoys of Alfonso, detected the fraud. Abbad, in a moment of folly and rage, crucified the Jew and imprisoned the Christian members of the mission. Alfonso retaliated with a destructive raid.
When Alfonso took Toledo in 1085, Abbad called in Yusuf ibn Tashfin, the Almoravid ruler. During the six years which preceded his deposition in 1091, Abbad behaved with valour on the field, but with much meanness and political folly. He endeavoured to curry favour with Yusuf ibn Tashfin by betraying the other Muslim princes to him, and intrigued to secure the alliance of Alfonso against the Almoravides. Probably during this period he surrendered his beautiful daughter Zaida to the Christian king, who made her his concubine - some authorities suggest he married her after she bore him a son, Sancho. The vacillations and submissions of Abbad did not save him from the fate which overtook his fellow-princes. Their scepticism and extortion had tired their subjects, and the mullahs gave Yusuf ibn Tashfin a Fatwa authorizing him to remove them in the interest of religion.
In 1091 the Almoravides stormed Seville. Abbad, who had fought bravely, weakly ordered his sons to surrender the fortresses they still held, in order to save his own life. He died in prison in Africa in 1095.